1. Field of the Invention
The invention is directed to a method for operating a hearing aid having: 1) an input transducer for picking up an input signal and converting it into an electrical signal, 2) a signal processing unit for processing and amplifying the electrical signal, and 3) an output transducer. The invention is also directed to a hearing aid for implementing the method.
2. Description of the Related Art
A plurality of hearing programs can be set in a known hearing aid for an optimized operation in different auditory situations. Switching between the individual hearing programs can be manual or automatic. For example, such a hearing aid is disclosed by U.S. Pat. No. 4,425,481.
The Prior Art also discloses hearing aids in which algorithms for signal processing in the hearing aid can be switched on and off for further adaptation to different auditory situations. These algorithms relate, for example, to the compression, the reduction of noise signals, or the boosting of speech signals.
Both the switching between various hearing programs as well as the activation of algorithms in the hearing aid can ensue manually or automatically. This usually produces disturbing acoustic effects and irritations in the perception of sound signals in associated natural auditory situations. These effects are usually expressed in the form of disturbing popping noises, unnatural level discontinuities or unnatural, sudden changes in timbre.
German Patent Document DE 195 42 961 C1 discloses a circuit for operating a hearing aid equipped with at least one variable operating parameter as well as a hearing aid itself, in which the operating parameter settings of an initial situation as well as of a target situation are defined in a memory arrangement, and a control unit can switch the operating parameter from the initial situation setting into the target situation setting over a certain time interval.
German Patent Document DE 195 34 981 A1 discloses a method for fine adaptation of hearing aids in which an evaluation step firstly evaluates the degree of optimization of parameters set at the hearing aid (e.g., using psycho-acoustic properties) and then in a following optimization step adjusts parameters in need of improvement. The degree of optimization to be evaluated or quantities that are responsible for this are determined in the framework of the evaluation step and/or the degree of adjustment of the parameter in need of improvement that is the determining factor in the optimization step is determined by algorithms or, respectively, rule sets based on fuzzy logic.
German Patent Document DE 198 59 171 C2 discloses an implantable hearing aid with a tinnitus masker or noiser in which has a digital signal processor that is designed both for editing the audio signal as well as for generating the signals needed for the tinnitus masking or noiser function and for merging the latter signals with the audio signal.